Metal-screw machine



(No Model.)

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N0. 267,215. Patented NOV. 7,1882..`

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A. JOHNSTON.

METAL SGREW MACHINE.

No. 267,215. Patented Nov. "7, 1882.

(No Model.)

JOHNSTON 3 Sheets-Sheet 3.

' METAL SCREW MACHINE.

Patented Nov. 7 18 To all whom it may concern:

UNITED STATES PATENT GEEICE.

ALLEN JoHNsTof, 0F OTTUMWA, IOWA.

METAL-SCREW MACHINE.

SPECIFICATION forming part of Letters Patent No. 267,215, dated November7, 1882.

Application filed July 5, 1882. (No model.)

Be it known that I, ALLEN JOHNSTON, of Ottumwa, county ol' Wapello, andState of Iowa, have invented a new and useful lmprovement in Metal-ScrewMachines, which improvement is fully set forth in the followingspecification.

This invention relates to automatic machines for making screws from arod or long screw-stock, and has particular reference to the mechanismfor bringing the toolssuch as lthe milling and threading, with orwithout other toolssuccessively into action upon the rod or screw-stock.These tools, as herein shown, are carried by independent longitudinalslides, which move in ways in a cross-slide and are brought successivelyinto line with the chuck by automatic mechanism which shifts saidcrossslide, and when brought in line are advanced independently, also byautomatic mechanism.

In theaccompanyingdrawingsisrepresented a machine constructed inaccordance with the invention, Figure 1 being a central "erticallongitudinal section; Fig. 2, a plan Fig. 3, a partial cross-section online w x, Fig. 1; Fig. 4, a partial view in horizontal section and inplan, Fig. 5, a vertical cross-section on line y y, Fig. 1 Fig. 6, abottom view in perspective of the longitudinal and cross slides; andFig. 7, a perspective view of an auxiliary slide, through which motionis imparted t0 the longitudinal slides.

Before entering upon a description of those parts of the machine whereinthe present invention resides it may be well brieiiy to explain theother elements, which may be of any ordinary or suitable construction,but which,

as shown, embody certain new improvements, subject-matter of myapplication tiled July 21, 1881, and numbered 38,250, whereof thepresent application is a division and continuation.

A is the machine-frame; B, the cam-shaft; C, the hollow chuck-spindle,having a pulley, C', fixed thereto, and geared to cam-shaft B throughtbetrain of spur-gears b b b2, b3 b4 b5 bG ZF bg; D, a tube slotted at theend and secured in the head of the chuck-spindle, the chuck beingscrewed thereto.

The chuck-jaws d are pressed inward to clamp the rod orv screw-stock bymeans of at intervals by means of a cam, d8, on the disk d, keyed to thecam-shaft B, the said cam d8 acting through a lever, d?, fulcrumed on anextension of the machine-frame, and engaging by a forked upper end acollar, dg, on the tube d3. When the pressure of the chuck-jaws isrelieved the rod or screw-stock is advanced by means of theclamp E. Thisclamp is carried by a slide, e2, working on the hollow rod E3, and movedforward by the spring E2 acting .against the pin e and back by the leverE acting against the set-screw c, tapped into the boss e8. The lever Eis operated by the cam 0115011 disk d1?, to withdraw the clamp E beforethe pressure of the chuck-jaws is released,

and to allow the spring E2 to'advance the feedclamp while said pressureis relieved. During this advance movement the clamp E, which has anupper and a lower jaw, is closed by the depression of the upper jawthrough the arm dI3 on the lever (Z7 and the link d. A tube, F, havingfriction-fingers at each end, and held loosely in the chuck-spindle bythe collar f, prevents the rod or screw-stock from being drawn back withthe feed-clamp, and otherwise assists in the feeding operation.

The milling-tool, or tool for turning down the rod to the diameterrequired for the screwthread, is of any ordinary or suitableconstruction.

The threading-tool, as shown, comprises a die carried by a spindle, L, asleeve, I, surrounding the spindle, a clutch, m, between the sleeve andthe spindle, a spring, l', tending to engage said clutch, a gear, M, forrotating the sleeve l and for revolving also the die and diespindle Lthrough said sleeve and the clutch m, and a safety stop-clutch, Z2 Z3 Z4Z5 ZG, for holding the die and die-spindle stationary when required. h

Motion is communicated to the gear M from a gear, N2, on the shaft N,through an idler, u?, supported by links u2 n3, so that the said gearsdo notinterfere with the lateral movement of IOS AVthe threading-tool,imparted as hereinafter detimes, except while unthreading the die, whenthe latter and its spindle are held stationary by the engagement of theprojection Z4 on the die-spindle with the projection Z3 on the clutchbarZ2, the clutch m being disengaged. rlhe clutch-bar Z2 is non-rotative,but is capable of a slight endwise movement against the pressure of thespring Z5, held in place by the screw Z6, so that, should theprojections Z3 Z4 not fairly engage, the spring will yield and preventthe stripping of the newly-formed thread from t-he rod or screw-stock.

For a more particular description of the various parts reference may behad to my beforementioned application, No. 38,250, wherein the sameletters of reference are employed.

The parts to which the present invention relates are as follows:

The tool-holder H is supported in guides or ways in the machine, and ismoved laterally back and forth by means of a cam, h4, bellcrank lever71,5, and connecting-rod hl. The cam 71,4 is formed on the periphery ofa drum, G, which is keyed to the cam-shaft B, so as to revolve with it.The bell-crank lever h5 is pivoted at h5 to the machine-frame, and therod hl is jointed at one end to the bell-crank lever and at the other tothe tool-holder H. Upon the tool-holder are carried aserics oftool-slides, H H2. rlwo are shown, one for the milling or turning-downtool and the other for the die or threading tool; but a larger numbercan be used, if necessary, for special purpose, or where deemeddesirable. The tool-slides are longitudinally movable at right angles tothe movenient of the tool-holder, and parallel or in line with the axisof the chuck-spindle. The rear end of the tool-holder (right-hand end,Figs. l and2) overhangs the longitudinal slide Kand a portion ofthemachine-frame, and is cut away underneath (see Fig. 5) to allow thenecessary freedom of motion to a projection, 7c, which operates thetool-slides. opening or groove, 7L', to receive the projection k. Theslide K moves back and forth in ways in the machine-frame, and isoperated by the cam h2, on the drum G and the pin h3, scoured to thesaid slide. A pin or stud, k2, extends into a hole in the tool-holder ateach advance of the slide K and prevents lateral motion of thetool-holder, and secures the exact centering of the tool in linewith-the axis of the chuck.

The cutting-oft'tool is shown at I), being adjustably connected with thetool-holder H.

The latter have each an In forming a screw the following operations takeplace: The rod is fed forward a distance equal to the length of thescrew; it is turned down to the required diameter by the millingtool; itis threaded by the die or threadingtool, and is severed from the rod bythe cutoff tool. During all these operations the chuckjaws d andchuck-spindle, the sleeve Z, surrounding the die-spindle, and thecamdrum G are revolved continuously, and during all, except that offeeding, the rod to be made into screws is also revolved. In feeding,the clamp E being open, the lever E is operated by the cam 115, and,acting against the screw e, pushes back the clamp E a distance equal tothe length ofa screw. This distance is regulated by turning the screw ein the lug e8, so that it will be struck sooner or later by thelever E.While the clamp is held back by the cam d the wedges d2 are withdrawn,thus releasing the pressure of the chuck-jaws eZ on the rod, and

thejaws of the clamp E are closed by the action of the cam d8 ou thelever C17. The cam ZB holds its lever in position until the lever E isreleased by its cam Zf and the feed-clamp has been advanced by thespring E2, when it also releases the lever dl. The feed-clamp is thus`released, the chuck-j aws are immediately closed by the action ofspringdu, and the rod rotates with the chuck. In the meantime the toolholder Hhas been moved by the cam h4, so that the milling-tool is in line withthe axis of the chuck. The slide K is now advanced by the cam h2,carrying with it the slide H ofthe milling-tool, and is then returned.The cam h4 moves the tool-holder H laterally and brings the die orthreading-tool in line with the axis of the chuck. By this lateralmovement the projection 7c on the slide K is made to engage with thegroove in the bottom of the tool-slide H2. The cam h2 again advances andreturns the slide K, which, at this reciprocation, carries with it theslide H2 of the threading-tool. During the advance ot' this tool thedie-spindle is revolved, being engaged by thesleeve Z through the clutchm. The return movement of the tool-slide, which is at first quick orsharp, causes the die-spindle L to be drawn forward in the sleeve Z,disengages clutch m, and effects the engagement of the projection Z4with the projection Z3 on the clutch-bar Z2. The die or threading-toolbeing held from turning by the projection on the clutch-bar, thecontinued revolution of the rod unthreads it. Another lateral movementof the tool-holder H brings the cutting-tool into action and severs thescrewjust made. The tool-holder is now moved back by the cam h4, tobring the milling-tool again in line, and during the operation a newfeed of the rod takes place.

Various modications may be made in the details of construction of theimproved screwmachines without departing from the spirit of theinvention, and portions of the invention may be used without the others.For example, a friction or two-motion feed-clamp of ordinary IOO IOS

IIO

, ting external threads.

gearing, which give quick motions followed by periods of rest. y

In another application, tiled July 2l, 1881, an arrangement is shownwhereby lateral movements are imparted to the chuck instead'of to thetools. The independent tool-slides could be used with such a chuck, andthe same arrangement of gearing as hereinbet'ore explained could be usedt0 convey the motion from the chuck-spindle to the die-spindle. The termdie-spindle77 is employed herein as a convenient term-for the spindle ofthe threadingtool, which, it is obvious, may be a tap for cuttinginternal threads as well as a die for cut- In such a case, themilling-tool would be a drill to bore out the hole to be threaded,instead of a turning-down tool. The term lateral movement,77 or flateral movementback and forth,7 is used herein in contradistinction tothe intermittent rotary movement of the ordinary turret employed inscrewmachines, and is not limited to a rectilinear movement in guides,which is the preferred movement, and which is therefore provided for inthe machine shown, but includes a vibratory or to-and-fro movement inshort arcs of a circle.

Having now fully described my said invention and the manner of carryingthe same into effect, I would observe, in conclusion, that I do notclaim in this application any of the improvements herein describedexcept those which relate to the means for bringing the toolssuccessively into operation on the rod or screw-stock, as the otherimprovements are reserved for my application N o. 38,250 5 but- Vhat Ido claim herein isl. llhe combination, with the chuck, the series of twoor more cutting-tools-such as turning, milling, or threading tools-thelateral-moving support or slide, and the series of independentlongitudinal slides carrying the tools above mentioned, of automaticmechanism comprising cams and connections, or their equivalents,foroperatingsaid laterally-movin g support,to bring the several toolssuccessively into line with the chuck, and for advancing thelongitudinal tool-slides separately and in succession, substantially asdescribed. p

2. The combination, with the hollow spindle, revolving chuck carried bysaid spindle, and the series of cutting-tools having longitudinalmotion, of the cams and connections, or equivalent automatic mechanism,for bringing by lateralmotion said chuck and the several toolssuccessively in line with each other, and for advancing said toolsseparately and in succession, substantially as described.

3. The combina-tion, with the laterally-moving tool-holder and theseries of cutting-tools carried by independent slides supported in waysof said tool-holder, ofthe automaticV mechanism comprising the cams andconnections, or their equivalents, for shifting said tool-holderlaterally, and for reciprocating the toolslides separately and insuccession, substantially as described.

In testimony whereof I have signed this specification in the presenceoftwo subscribing witnesses.

ALLEN JOHNSTON.

Witnesses A. G. HARRow, J. T. HAGKWORTH.

